9813022 McMeeking The microelectromechanics of perovskite ferroelectric ceramics (PFC) and single crystals is investigated. Simple experiments are conducted to study the swithcing response of polycrystalline and single crystal PFCs in the presence of simulataneous electric field and mechanical stress. Models for nonlinear behavior of PFC combined with the experimental data are used to develop phenomenological constitutive laws to predict the response of polycrystalline ceramics and single crystals. A fracture mechanics approach for PFCs is also developed. ***